Viewing archive of Thursday, 11 August 2011

Solar activity report

Any mentioned solar flare in this report has a scaling factor applied by the Space Weather Prediction Center (SWPC). Because of the SWPC scaling factor, solar flares are reported as 42% smaller than for the science quality data. The scaling factor has been removed from our archived solar flare data to reflect the true physical units.
Report of Solar-Geophysical Activity 2011 Aug 11 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 223 Issued at 2200Z on 11 Aug 2011

IA. Analysis of Solar Active Regions and Activity from 10-2100Z to 11-2100Z

Solar activity was low. Region 1263 (N17, L=301) produced a C6 x-ray flare from beyond the west limb. New regions 1269 (S22E17) and 1270 (S23E54) were numbered today; both are small and magnetically simple. A CME was observed on the west limb, evident in SOHO/LASCO C2 imagery at 11/1036Z. Material movement and subsequent darkening was observed in STEREO-A EUV imagery beginning at approximately 11/1005Z. This CME is not expected to be geoeffective.
IB. Solar Activity Forecast
Solar activity is expected to be very low to low. There is a chance for a C class x-ray event throughout the period.
IIA. Geophysical Activity Summary 10-2100Z to 11-2100Z
The geomagnetic field was quiet. Solar wind speed at the ACE spacecraft continued to decline and ended the period near 400 km/s. The Phi angle briefly switched to negative between 11/10Z and 11/12Z. The Bz component of the interplanetary magnetic field remained around zero. A shock was observed in the STEREO-A beacon data at roughly 11/0600Z. This is most likely the arrival of the 09 August CME from Region 1263. The greater than 2 MeV electron flux at geosynchronous orbit was at high levels throughout the period.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be predominantly quiet for the next three days (12-14 August).
III. Event Probabilities 12 Aug to 14 Aug
Class M05%05%05%
Class X01%01%01%
Proton01%01%01%
PCAFGreen
IV. Penticton 10.7 cm Flux
  Observed       11 Aug 084
  Predicted   12 Aug-14 Aug  085/085/090
  90 Day Mean        11 Aug 096
V. Geomagnetic A Indices
  Observed Afr/Ap 10 Aug  008/007
  Estimated     Afr/Ap 11 Aug  005/004
  Predicted    Afr/Ap 12 Aug-14 Aug  005/005-005/005-005/005
VI. Geomagnetic Activity Probabilities 12 Aug to 14 Aug
A. Middle Latitudes
Active15%05%05%
Minor storm05%05%05%
Major-severe storm01%01%01%
B. High Latitudes
Active20%10%20%
Minor storm10%05%10%
Major-severe storm05%01%05%

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